/* $NetBSD: ip6_etherip.c,v 1.21.8.1 2018/04/05 14:31:19 martin Exp $ */ /* * Copyright (c) 2006, Hans Rosenfeld * 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 Hans Rosenfeld nor the names of his * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * 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. */ /* * 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. */ #include __KERNEL_RCSID(0, "$NetBSD: ip6_etherip.c,v 1.21.8.1 2018/04/05 14:31:19 martin Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #endif #ifdef INET6 #include #include #include #include #include #endif #include #include #include #include int ip6_etherip_output(struct ifnet *ifp, struct mbuf *m) { struct rtentry *rt; struct etherip_softc *sc = (struct etherip_softc *)ifp->if_softc; struct sockaddr_in6 *sin6_src, *sin6_dst; struct ip6_hdr *ip6; /* capsule IP header, host byte ordered */ struct etherip_header eiphdr; int proto, error; union { struct sockaddr dst; struct sockaddr_in6 dst6; } u; sin6_src = (struct sockaddr_in6 *)sc->sc_src; sin6_dst = (struct sockaddr_in6 *)sc->sc_dst; if (sin6_src == NULL || sin6_dst == NULL || sin6_src->sin6_family != AF_INET6 || sin6_dst->sin6_family != AF_INET6) { m_freem(m); return EAFNOSUPPORT; } /* reset broadcast/multicast flags */ m->m_flags &= ~(M_BCAST|M_MCAST); KASSERT((m->m_flags & M_PKTHDR) != 0); proto = IPPROTO_ETHERIP; /* fill and prepend Ethernet-in-IP header */ eiphdr.eip_ver = ETHERIP_VERSION & ETHERIP_VER_VERS_MASK; eiphdr.eip_pad = 0; M_PREPEND(m, sizeof(struct etherip_header), M_DONTWAIT); if (m == NULL) return ENOBUFS; if (M_UNWRITABLE(m, sizeof(struct etherip_header))) { m = m_pullup(m, sizeof(struct etherip_header)); if (m == NULL) return ENOBUFS; } memcpy(mtod(m, struct etherip_header *), &eiphdr, sizeof(struct etherip_header)); /* 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_nxt = proto; ip6->ip6_hlim = ETHERIP_TTL; ip6->ip6_src = sin6_src->sin6_addr; /* bidirectional configured tunnel mode */ if (!IN6_IS_ADDR_UNSPECIFIED(&sin6_dst->sin6_addr)) ip6->ip6_dst = sin6_dst->sin6_addr; else { m_freem(m); return ENETUNREACH; } sockaddr_in6_init(&u.dst6, &sin6_dst->sin6_addr, 0, 0, 0); if ((rt = rtcache_lookup(&sc->sc_ro, &u.dst)) == NULL) { m_freem(m); return ENETUNREACH; } /* if it constitutes infinite encapsulation, punt. */ if (rt->rt_ifp == ifp) { rtcache_unref(rt, &sc->sc_ro); rtcache_free(&sc->sc_ro); m_freem(m); return ENETUNREACH; /* XXX */ } rtcache_unref(rt, &sc->sc_ro); /* * 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->sc_ro, IPV6_MINMTU, NULL, NULL, NULL); return error; } int ip6_etherip_input(struct mbuf **mp, int *offp, int proto) { struct mbuf *m = *mp; int off = *offp; struct etherip_softc *sc; const struct ip6_hdr *ip6; struct sockaddr_in6 *src6, *dst6; struct ifnet *ifp = NULL; int s; if (proto != IPPROTO_ETHERIP) { m_freem(m); IP6_STATINC(IP6_STAT_NOGIF); return IPPROTO_DONE; } ip6 = mtod(m, const struct ip6_hdr *); /* find device configured for this packet's src and dst */ LIST_FOREACH(sc, ðerip_softc_list, etherip_list) { if (!sc->sc_src || !sc->sc_dst) continue; if (sc->sc_src->sa_family != AF_INET6 || sc->sc_dst->sa_family != AF_INET6) continue; src6 = (struct sockaddr_in6 *)sc->sc_src; dst6 = (struct sockaddr_in6 *)sc->sc_dst; if (!IN6_ARE_ADDR_EQUAL(&src6->sin6_addr, &ip6->ip6_dst) || !IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr, &ip6->ip6_src)) continue; ifp = &sc->sc_ec.ec_if; break; } /* no matching device found */ if (!ifp) { m_freem(m); IP6_STATINC(IP6_STAT_ODROPPED); return IPPROTO_DONE; } m_adj(m, off); /* * Section 4 of RFC 3378 requires that the EtherIP header of incoming * packets is verified to contain the correct values in the version and * reserved fields, and packets with wrong values be dropped. * * There is some discussion about what exactly the header should look * like, the RFC is not very clear there. To be compatible with broken * implementations, we don't check the header on incoming packets, * relying on the ethernet code to filter out garbage. * * The header we use for sending is compatible with the original * implementation in OpenBSD, which was used in former NetBSD versions * and is used in FreeBSD. One Linux implementation is known to use the * same value. */ m_adj(m, sizeof(struct etherip_header)); m = m_pullup(m, sizeof(struct ether_header)); if (m == NULL) { ifp->if_ierrors++; return IPPROTO_DONE; } m_set_rcvif(m, ifp); m->m_flags &= ~(M_BCAST|M_MCAST); s = splnet(); if_input(ifp, m); splx(s); return IPPROTO_DONE; }