406 lines
9.7 KiB
C
406 lines
9.7 KiB
C
/* $NetBSD: in_gif.c,v 1.62 2012/01/09 14:31:22 liamjfoy Exp $ */
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/* $KAME: in_gif.c,v 1.66 2001/07/29 04:46:09 itojun Exp $ */
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/*
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* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: in_gif.c,v 1.62 2012/01/09 14:31:22 liamjfoy Exp $");
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#include "opt_inet.h"
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#include "opt_iso.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/socket.h>
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#include <sys/sockio.h>
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#include <sys/mbuf.h>
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#include <sys/errno.h>
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#include <sys/ioctl.h>
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#include <sys/syslog.h>
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#include <sys/protosw.h>
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#include <sys/kernel.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/in_gif.h>
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#include <netinet/in_var.h>
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#include <netinet/ip_encap.h>
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#include <netinet/ip_ecn.h>
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#ifdef INET6
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#include <netinet/ip6.h>
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#endif
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#include <net/if_gif.h>
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#include "gif.h"
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#include <net/net_osdep.h>
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static int gif_validate4(const struct ip *, struct gif_softc *,
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struct ifnet *);
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#if NGIF > 0
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int ip_gif_ttl = GIF_TTL;
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#else
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int ip_gif_ttl = 0;
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#endif
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const struct protosw in_gif_protosw =
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{ SOCK_RAW, &inetdomain, 0/* IPPROTO_IPV[46] */, PR_ATOMIC|PR_ADDR,
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in_gif_input, rip_output, 0, rip_ctloutput,
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rip_usrreq,
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0, 0, 0, 0,
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};
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int
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in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
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{
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struct rtentry *rt;
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struct gif_softc *sc = ifp->if_softc;
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struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
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struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
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struct ip iphdr; /* capsule IP header, host byte ordered */
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int proto, error;
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u_int8_t tos;
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union {
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struct sockaddr dst;
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struct sockaddr_in dst4;
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} u;
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if (sin_src == NULL || sin_dst == NULL ||
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sin_src->sin_family != AF_INET ||
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sin_dst->sin_family != AF_INET) {
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m_freem(m);
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return EAFNOSUPPORT;
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}
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switch (family) {
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#ifdef INET
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case AF_INET:
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{
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const struct ip *ip;
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proto = IPPROTO_IPV4;
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if (m->m_len < sizeof(*ip)) {
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m = m_pullup(m, sizeof(*ip));
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if (m == NULL)
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return ENOBUFS;
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}
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ip = mtod(m, const struct ip *);
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tos = ip->ip_tos;
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break;
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}
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#endif /* INET */
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#ifdef INET6
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case AF_INET6:
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{
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const struct ip6_hdr *ip6;
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proto = IPPROTO_IPV6;
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if (m->m_len < sizeof(*ip6)) {
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m = m_pullup(m, sizeof(*ip6));
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if (m == NULL)
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return ENOBUFS;
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}
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ip6 = mtod(m, const struct ip6_hdr *);
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tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
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break;
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}
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#endif /* INET6 */
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#ifdef ISO
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case AF_ISO:
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proto = IPPROTO_EON;
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tos = 0;
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break;
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#endif
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default:
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#ifdef DEBUG
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printf("in_gif_output: warning: unknown family %d passed\n",
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family);
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#endif
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m_freem(m);
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return EAFNOSUPPORT;
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}
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memset(&iphdr, 0, sizeof(iphdr));
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iphdr.ip_src = sin_src->sin_addr;
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/* bidirectional configured tunnel mode */
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if (sin_dst->sin_addr.s_addr != INADDR_ANY)
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iphdr.ip_dst = sin_dst->sin_addr;
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else {
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m_freem(m);
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return ENETUNREACH;
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}
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iphdr.ip_p = proto;
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/* version will be set in ip_output() */
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iphdr.ip_ttl = ip_gif_ttl;
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iphdr.ip_len = htons(m->m_pkthdr.len + sizeof(struct ip));
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if (ifp->if_flags & IFF_LINK1)
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ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
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else
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ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
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/* prepend new IP header */
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M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
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/* XXX Is m_pullup really necessary after M_PREPEND? */
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if (m != NULL && M_UNWRITABLE(m, sizeof(struct ip)))
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m = m_pullup(m, sizeof(struct ip));
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if (m == NULL)
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return ENOBUFS;
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bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
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sockaddr_in_init(&u.dst4, &sin_dst->sin_addr, 0);
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if ((rt = rtcache_lookup(&sc->gif_ro, &u.dst)) == NULL) {
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m_freem(m);
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return ENETUNREACH;
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}
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/* If the route constitutes infinite encapsulation, punt. */
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if (rt->rt_ifp == ifp) {
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rtcache_free(&sc->gif_ro);
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m_freem(m);
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return ENETUNREACH; /*XXX*/
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}
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error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
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return (error);
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}
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void
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in_gif_input(struct mbuf *m, ...)
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{
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int off, proto;
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struct ifnet *gifp = NULL;
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const struct ip *ip;
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va_list ap;
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int af;
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u_int8_t otos;
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va_start(ap, m);
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off = va_arg(ap, int);
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proto = va_arg(ap, int);
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va_end(ap);
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ip = mtod(m, const struct ip *);
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gifp = (struct ifnet *)encap_getarg(m);
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if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
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m_freem(m);
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ip_statinc(IP_STAT_NOGIF);
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return;
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}
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#ifndef GIF_ENCAPCHECK
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if (!gif_validate4(ip, gifp->if_softc, m->m_pkthdr.rcvif)) {
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m_freem(m);
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ip_statinc(IP_STAT_NOGIF);
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return;
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}
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#endif
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otos = ip->ip_tos;
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m_adj(m, off);
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switch (proto) {
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#ifdef INET
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case IPPROTO_IPV4:
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{
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struct ip *xip;
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af = AF_INET;
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if (M_UNWRITABLE(m, sizeof(*xip))) {
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if ((m = m_pullup(m, sizeof(*xip))) == NULL)
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return;
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}
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xip = mtod(m, struct ip *);
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if (gifp->if_flags & IFF_LINK1)
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ip_ecn_egress(ECN_ALLOWED, &otos, &xip->ip_tos);
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else
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ip_ecn_egress(ECN_NOCARE, &otos, &xip->ip_tos);
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break;
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}
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#endif
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#ifdef INET6
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case IPPROTO_IPV6:
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{
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struct ip6_hdr *ip6;
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u_int8_t itos;
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af = AF_INET6;
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if (M_UNWRITABLE(m, sizeof(*ip6))) {
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if ((m = m_pullup(m, sizeof(*ip6))) == NULL)
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return;
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}
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ip6 = mtod(m, struct ip6_hdr *);
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itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
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if (gifp->if_flags & IFF_LINK1)
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ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
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else
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ip_ecn_egress(ECN_NOCARE, &otos, &itos);
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ip6->ip6_flow &= ~htonl(0xff << 20);
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ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
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break;
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}
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#endif /* INET6 */
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#ifdef ISO
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case IPPROTO_EON:
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af = AF_ISO;
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break;
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#endif
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default:
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ip_statinc(IP_STAT_NOGIF);
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m_freem(m);
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return;
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}
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gif_input(m, af, gifp);
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return;
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}
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/*
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* validate outer address.
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*/
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static int
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gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
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{
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struct sockaddr_in *src, *dst;
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struct in_ifaddr *ia4;
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src = (struct sockaddr_in *)sc->gif_psrc;
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dst = (struct sockaddr_in *)sc->gif_pdst;
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/* check for address match */
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if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
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dst->sin_addr.s_addr != ip->ip_src.s_addr)
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return 0;
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/* martian filters on outer source - NOT done in ip_input! */
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if (IN_MULTICAST(ip->ip_src.s_addr))
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return 0;
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switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
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case 0: case 127: case 255:
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return 0;
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}
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/* reject packets with broadcast on source */
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TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_list) {
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if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
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continue;
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if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
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return 0;
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}
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/* ingress filters on outer source */
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if ((sc->gif_if.if_flags & IFF_LINK2) == 0 && ifp) {
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union {
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struct sockaddr sa;
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struct sockaddr_in sin;
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} u;
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struct rtentry *rt;
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sockaddr_in_init(&u.sin, &ip->ip_src, 0);
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rt = rtalloc1(&u.sa, 0);
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if (rt == NULL || rt->rt_ifp != ifp) {
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#if 0
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log(LOG_WARNING, "%s: packet from 0x%x dropped "
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"due to ingress filter\n", if_name(&sc->gif_if),
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(u_int32_t)ntohl(u.sin.sin_addr.s_addr));
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#endif
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if (rt != NULL)
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rtfree(rt);
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return 0;
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}
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rtfree(rt);
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}
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return 32 * 2;
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}
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#ifdef GIF_ENCAPCHECK
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/*
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* we know that we are in IFF_UP, outer address available, and outer family
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* matched the physical addr family. see gif_encapcheck().
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*/
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int
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gif_encapcheck4(struct mbuf *m, int off, int proto, void *arg)
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{
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struct ip ip;
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struct gif_softc *sc;
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struct ifnet *ifp;
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/* sanity check done in caller */
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sc = arg;
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m_copydata(m, 0, sizeof(ip), &ip);
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ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
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return gif_validate4(&ip, sc, ifp);
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}
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#endif
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int
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in_gif_attach(struct gif_softc *sc)
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{
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#ifndef GIF_ENCAPCHECK
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struct sockaddr_in mask4;
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memset(&mask4, 0, sizeof(mask4));
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mask4.sin_len = sizeof(struct sockaddr_in);
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mask4.sin_addr.s_addr = ~0;
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if (!sc->gif_psrc || !sc->gif_pdst)
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return EINVAL;
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sc->encap_cookie4 = encap_attach(AF_INET, -1, sc->gif_psrc,
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(struct sockaddr *)&mask4, sc->gif_pdst, (struct sockaddr *)&mask4,
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(const struct protosw *)&in_gif_protosw, sc);
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#else
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sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
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&in_gif_protosw, sc);
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#endif
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if (sc->encap_cookie4 == NULL)
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return EEXIST;
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return 0;
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}
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int
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in_gif_detach(struct gif_softc *sc)
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{
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int error;
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error = encap_detach(sc->encap_cookie4);
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if (error == 0)
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sc->encap_cookie4 = NULL;
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rtcache_free(&sc->gif_ro);
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return error;
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}
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