/* $KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $ */ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (C) 2000 WIDE Project. * Copyright (c) 2010 Hiroki Sato * Copyright (c) 2013 Ermal Luci * Copyright (c) 2017-2021 Rubicon Communications, LLC (Netgate) * 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. */ /* * 6to4 interface, based on RFC3056. * * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting. * There is no address mapping defined from IPv6 multicast address to IPv4 * address. Therefore, we do not have IFF_MULTICAST on the interface. * * Due to the lack of address mapping for link-local addresses, we cannot * throw packets toward link-local addresses (fe80::x). Also, we cannot throw * packets to link-local multicast addresses (ff02::x). * * Here are interesting symptoms due to the lack of link-local address: * * Unicast routing exchange: * - RIPng: Impossible. Uses link-local multicast packet toward ff02::9, * and link-local addresses as nexthop. * - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address * assigned to the link, and makes use of them. Also, HELLO packets use * link-local multicast addresses (ff02::5 and ff02::6). * - BGP4+: Maybe. You can only use global address as nexthop, and global * address as TCP endpoint address. * * Multicast routing protocols: * - PIM: Hello packet cannot be used to discover adjacent PIM routers. * Adjacent PIM routers must be configured manually (is it really spec-wise * correct thing to do?). * * ICMPv6: * - Redirects cannot be used due to the lack of link-local address. * * stf interface does not have, and will not need, a link-local address. * It seems to have no real benefit and does not help the above symptoms much. * Even if we assign link-locals to interface, we cannot really * use link-local unicast/multicast on top of 6to4 cloud (since there's no * encapsulation defined for link-local address), and the above analysis does * not change. RFC3056 does not mandate the assignment of link-local address * either. * * 6to4 interface has security issues. Refer to * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt * for details. The code tries to filter out some of malicious packets. * Note that there is no way to be 100% secure. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include SDT_PROVIDER_DEFINE(if_stf); SDT_PROBE_DEFINE3(if_stf, , encapcheck, in, "struct mbuf *", "int", "int"); SDT_PROBE_DEFINE0(if_stf, , encapcheck, accept); SDT_PROBE_DEFINE3(if_stf, , getsrcifa6, in, "struct ifnet *", "struct in6_addr *", "struct in6_addr *"); SDT_PROBE_DEFINE2(if_stf, , getsrcifa6, found, "struct in6_addr *", "struct in6_addr *"); SDT_PROBE_DEFINE0(if_stf, , getsrcifa6, notfound); SDT_PROBE_DEFINE4(if_stf, , stf_output, in, "struct ifnet *", "struct mbuf *", "struct sockaddr *", "struct route *"); SDT_PROBE_DEFINE2(if_stf, , stf_output, error, "int", "int"); SDT_PROBE_DEFINE1(if_stf, , stf_output, out, "int"); SDT_PROBE_DEFINE3(if_stf, , checkaddr6, in, "struct stf_softc *", "struct in6_addr *", "struct ifnet *"); SDT_PROBE_DEFINE2(if_stf, , checkaddr6, out, "int", "int"); SDT_PROBE_DEFINE3(if_stf, , stf_input, in, "struct mbuf *", "int", "int"); SDT_PROBE_DEFINE2(if_stf, , stf_input, out, "int", "int"); SDT_PROBE_DEFINE3(if_stf, , ioctl, sv4net, "struct in_addr *", "struct in_addr *", "int"); SDT_PROBE_DEFINE1(if_stf, , ioctl, sdstv4, "struct in_addr *"); SDT_PROBE_DEFINE1(if_stf, , ioctl, ifaddr, "struct ifaddr *"); SDT_PROBE_DEFINE4(if_stf, , getin4addr_in6, out, "struct in6_addr *", "struct in6_addr *", "struct in6_addr *", "struct sockaddr_in *"); SDT_PROBE_DEFINE2(if_stf, , getin4addr, in, "struct in6_addr *", "struct in6_addr *"); SDT_PROBE_DEFINE1(if_stf, , getin4addr, out, "struct sockaddr_in *"); SYSCTL_DECL(_net_link); static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, "6to4 Interface"); static int stf_permit_rfc1918 = 0; SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RWTUN, &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses"); #define STFUNIT 0 #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002) /* * XXX: Return a pointer with 16-bit aligned. Don't cast it to * struct in_addr *; use bcopy() instead. */ #define GET_V4(x) (&(x)->s6_addr16[1]) struct stf_softc { struct ifnet *sc_ifp; in_addr_t braddr; /* Border relay IPv4 address */ in_addr_t srcv4_addr; /* Our IPv4 WAN address */ u_int v4prefixlen; /* How much of the v4 address to include in our address. */ u_int sc_fibnum; const struct encaptab *encap_cookie; }; #define STF2IFP(sc) ((sc)->sc_ifp) static const char stfname[] = "stf"; static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface"); static const int ip_stf_ttl = 40; static int in_stf_input(struct mbuf *, int, int, void *); static char *stfnames[] = {"stf0", "stf", "6to4", NULL}; static int stfmodevent(module_t, int, void *); static int stf_encapcheck(const struct mbuf *, int, int, void *); static int stf_getsrcifa6(struct ifnet *, struct in6_addr *, struct in6_addr *); static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *, struct route *); static int isrfc1918addr(struct in_addr *); static int stf_checkaddr4(struct stf_softc *, struct in_addr *, struct ifnet *); static int stf_checkaddr6(struct stf_softc *, struct in6_addr *, struct ifnet *); static struct sockaddr_in *stf_getin4addr_in6(struct stf_softc *, struct sockaddr_in *, struct in6_addr, struct in6_addr, struct in6_addr); static struct sockaddr_in *stf_getin4addr(struct stf_softc *, struct sockaddr_in *, struct in6_addr, struct in6_addr); static int stf_ioctl(struct ifnet *, u_long, caddr_t); VNET_DEFINE_STATIC(struct if_clone *, stf_cloner); #define V_stf_cloner VNET(stf_cloner) static const struct encap_config ipv4_encap_cfg = { .proto = IPPROTO_IPV6, .min_length = sizeof(struct ip), .exact_match = (sizeof(in_addr_t) << 3) + 8, .check = stf_encapcheck, .input = in_stf_input }; static int stf_clone_match(struct if_clone *ifc, const char *name) { int i; for(i = 0; stfnames[i] != NULL; i++) { if (strcmp(stfnames[i], name) == 0) return (1); } return (0); } static int stf_clone_create(struct if_clone *ifc, char *name, size_t len, struct ifc_data *ifd, struct ifnet **ifpp) { char *dp; int err, unit, wildcard; struct stf_softc *sc; struct ifnet *ifp; err = ifc_name2unit(name, &unit); if (err != 0) return (err); wildcard = (unit < 0); /* * We can only have one unit, but since unit allocation is * already locked, we use it to keep from allocating extra * interfaces. */ unit = STFUNIT; err = ifc_alloc_unit(ifc, &unit); if (err != 0) return (err); sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); ifp = STF2IFP(sc) = if_alloc(IFT_STF); if (ifp == NULL) { free(sc, M_STF); ifc_free_unit(ifc, unit); return (ENOSPC); } ifp->if_softc = sc; sc->sc_fibnum = curthread->td_proc->p_fibnum; /* * Set the name manually rather then using if_initname because * we don't conform to the default naming convention for interfaces. * In the wildcard case, we need to update the name. */ if (wildcard) { for (dp = name; *dp != '\0'; dp++); if (snprintf(dp, len - (dp-name), "%d", unit) > len - (dp-name) - 1) { /* * This can only be a programmer error and * there's no straightforward way to recover if * it happens. */ panic("if_clone_create(): interface name too long"); } } strlcpy(ifp->if_xname, name, IFNAMSIZ); ifp->if_dname = stfname; ifp->if_dunit = IF_DUNIT_NONE; sc->encap_cookie = ip_encap_attach(&ipv4_encap_cfg, sc, M_WAITOK); ifp->if_mtu = IPV6_MMTU; ifp->if_ioctl = stf_ioctl; ifp->if_output = stf_output; ifp->if_snd.ifq_maxlen = ifqmaxlen; if_attach(ifp); bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); *ifpp = ifp; return (0); } static int stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) { struct stf_softc *sc = ifp->if_softc; int err __unused; err = ip_encap_detach(sc->encap_cookie); KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); bpfdetach(ifp); if_detach(ifp); if_free(ifp); free(sc, M_STF); ifc_free_unit(ifc, STFUNIT); return (0); } static void vnet_stf_init(const void *unused __unused) { struct if_clone_addreq req = { .match_f = stf_clone_match, .create_f = stf_clone_create, .destroy_f = stf_clone_destroy, }; V_stf_cloner = ifc_attach_cloner(stfname, &req); } VNET_SYSINIT(vnet_stf_init, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_stf_init, NULL); static void vnet_stf_uninit(const void *unused __unused) { if_clone_detach(V_stf_cloner); V_stf_cloner = NULL; } VNET_SYSUNINIT(vnet_stf_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_stf_uninit, NULL); static int stfmodevent(module_t mod, int type, void *data) { switch (type) { case MOD_LOAD: /* Done in vnet_stf_init() */ break; case MOD_UNLOAD: /* Done in vnet_stf_uninit() */ break; default: return (EOPNOTSUPP); } return (0); } static moduledata_t stf_mod = { "if_stf", stfmodevent, 0 }; DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); MODULE_VERSION(if_stf, 2); static int stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg) { struct ip ip; struct stf_softc *sc; struct in6_addr addr6, mask6; struct sockaddr_in sin4addr, sin4mask; SDT_PROBE3(if_stf, , encapcheck, in, m, off, proto); sc = (struct stf_softc *)arg; if (sc == NULL) return (0); if ((STF2IFP(sc)->if_flags & IFF_UP) == 0) return (0); /* IFF_LINK0 means "no decapsulation" */ if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0) return (0); if (proto != IPPROTO_IPV6) return (0); m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); if (ip.ip_v != 4) return (0); if (stf_getsrcifa6(STF2IFP(sc), &addr6, &mask6) != 0) return (0); if (sc->srcv4_addr != INADDR_ANY) { sin4addr.sin_addr.s_addr = sc->srcv4_addr; sin4addr.sin_family = AF_INET; } else if (stf_getin4addr(sc, &sin4addr, addr6, mask6) == NULL) return (0); if (sin4addr.sin_addr.s_addr != ip.ip_dst.s_addr) return (0); if (IN6_IS_ADDR_6TO4(&addr6)) { /* * 6to4 (RFC 3056). * Check if IPv4 src matches the IPv4 address derived * from the local 6to4 address masked by prefixmask. * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24 * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24 */ memcpy(&sin4mask.sin_addr, GET_V4(&mask6), sizeof(sin4mask.sin_addr)); if ((sin4addr.sin_addr.s_addr & sin4mask.sin_addr.s_addr) != (ip.ip_src.s_addr & sin4mask.sin_addr.s_addr)) return (0); } else { /* 6rd (RFC 5569) */ /* * No restriction on the src address in the case of * 6rd because the stf(4) interface always has a * prefix which covers whole of IPv4 src address * range. So, stf_output() will catch all of * 6rd-capsuled IPv4 traffic with suspicious inner dst * IPv4 address (i.e. the IPv6 destination address is * one the admin does not like to route to outside), * and then it discard them silently. */ } SDT_PROBE0(if_stf, , encapcheck, accept); /* stf interface makes single side match only */ return (32); } static int stf_getsrcifa6(struct ifnet *ifp, struct in6_addr *addr, struct in6_addr *mask) { struct ifaddr *ia; struct in_ifaddr *ia4; struct in6_addr addr6, mask6; struct sockaddr_in sin4; struct stf_softc *sc; struct in_addr in; NET_EPOCH_ASSERT(); sc = ifp->if_softc; SDT_PROBE3(if_stf, , getsrcifa6, in, ifp, addr, mask); CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) { if (ia->ifa_addr->sa_family != AF_INET6) continue; addr6 = *IFA_IN6(ia); mask6 = *IFA_MASKIN6(ia); if (sc->srcv4_addr != INADDR_ANY) bcopy(&sc->srcv4_addr, &in, sizeof(in)); else { if (stf_getin4addr(sc, &sin4, addr6, mask6) == NULL) continue; bcopy(&sin4.sin_addr, &in, sizeof(in)); } CK_LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash) if (ia4->ia_addr.sin_addr.s_addr == in.s_addr) break; if (ia4 == NULL) continue; *addr = addr6; *mask = mask6; SDT_PROBE2(if_stf, , getsrcifa6, found, addr, mask); return (0); } SDT_PROBE0(if_stf, , getsrcifa6, notfound); return (ENOENT); } static int stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, struct route *ro) { struct stf_softc *sc; const struct sockaddr_in6 *dst6; struct sockaddr_in dst4, src4; u_int8_t tos; struct ip *ip; struct ip6_hdr *ip6; struct in6_addr addr6, mask6; int error; SDT_PROBE4(if_stf, , stf_output, in, ifp, m, dst, ro); #ifdef MAC error = mac_ifnet_check_transmit(ifp, m); if (error) { m_freem(m); SDT_PROBE2(if_stf, , stf_output, error, error, __LINE__); return (error); } #endif sc = ifp->if_softc; dst6 = (const struct sockaddr_in6 *)dst; /* just in case */ if ((ifp->if_flags & IFF_UP) == 0) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); SDT_PROBE2(if_stf, , stf_output, error, ENETDOWN, __LINE__); return (ENETDOWN); } /* * If we don't have an ip4 address that match my inner ip6 address, * we shouldn't generate output. Without this check, we'll end up * using wrong IPv4 source. */ if (stf_getsrcifa6(ifp, &addr6, &mask6) != 0) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); SDT_PROBE2(if_stf, , stf_output, error, ENETDOWN, __LINE__); return (ENETDOWN); } if (m->m_len < sizeof(*ip6)) { m = m_pullup(m, sizeof(*ip6)); if (!m) { if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); SDT_PROBE2(if_stf, , stf_output, error, ENOBUFS, __LINE__); return (ENOBUFS); } } ip6 = mtod(m, struct ip6_hdr *); tos = IPV6_TRAFFIC_CLASS(ip6); /* * Pickup the right outer dst addr from the list of candidates. * ip6_dst has priority as it may be able to give us shorter IPv4 hops. */ if (stf_getin4addr_in6(sc, &dst4, addr6, mask6, ip6->ip6_dst) == NULL) { if (sc->braddr != INADDR_ANY) dst4.sin_addr.s_addr = sc->braddr; else if (stf_getin4addr_in6(sc, &dst4, addr6, mask6, dst6->sin6_addr) == NULL) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); SDT_PROBE2(if_stf, , stf_output, error, ENETUNREACH, __LINE__); return (ENETUNREACH); } } if (bpf_peers_present(ifp->if_bpf)) { /* * We need to prepend the address family as * a four byte field. Cons up a dummy header * to pacify bpf. This is safe because bpf * will only read from the mbuf (i.e., it won't * try to free it or keep a pointer a to it). */ u_int af = AF_INET6; bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); } M_PREPEND(m, sizeof(struct ip), M_NOWAIT); if (m == NULL) { if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); SDT_PROBE2(if_stf, , stf_output, error, ENOBUFS, __LINE__); return (ENOBUFS); } ip = mtod(m, struct ip *); bzero(ip, sizeof(*ip)); if (sc->srcv4_addr != INADDR_ANY) src4.sin_addr.s_addr = sc->srcv4_addr; else if (stf_getin4addr(sc, &src4, addr6, mask6) == NULL) { m_freem(m); if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); SDT_PROBE2(if_stf, , stf_output, error, ENETUNREACH, __LINE__); return (ENETUNREACH); } bcopy(&src4.sin_addr, &ip->ip_src, sizeof(ip->ip_src)); bcopy(&dst4.sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)); ip->ip_p = IPPROTO_IPV6; ip->ip_ttl = ip_stf_ttl; ip->ip_len = htons(m->m_pkthdr.len); if (ifp->if_flags & IFF_LINK1) ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos); else ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos); M_SETFIB(m, sc->sc_fibnum); if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); error = ip_output(m, NULL, NULL, 0, NULL, NULL); SDT_PROBE1(if_stf, , stf_output, out, error); return (error); } static int isrfc1918addr(struct in_addr *in) { /* * returns 1 if private address range: * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 */ if (stf_permit_rfc1918 == 0 && ( (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 || (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 || (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168)) return (1); return (0); } static int stf_checkaddr4(struct stf_softc *sc, struct in_addr *in, struct ifnet *inifp) { struct in_ifaddr *ia4; /* * reject packets with the following address: * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8 */ if (IN_MULTICAST(ntohl(in->s_addr))) return (-1); switch ((ntohl(in->s_addr) & 0xff000000) >> 24) { case 0: case 127: case 255: return (-1); } /* * reject packets with broadcast */ CK_STAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) { if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0) continue; if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) { return (-1); } } /* * perform ingress filter */ if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { struct nhop_object *nh; NET_EPOCH_ASSERT(); nh = fib4_lookup(sc->sc_fibnum, *in, 0, 0, 0); if (nh == NULL) return (-1); if (nh->nh_ifp != inifp) return (-1); } return (0); } static int stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp) { SDT_PROBE3(if_stf, , checkaddr6, in, sc, in6, inifp); /* * check 6to4 addresses */ if (IN6_IS_ADDR_6TO4(in6)) { struct in_addr in4; int ret; bcopy(GET_V4(in6), &in4, sizeof(in4)); ret = stf_checkaddr4(sc, &in4, inifp); SDT_PROBE2(if_stf, , checkaddr6, out, ret, __LINE__); return (ret); } /* * reject anything that look suspicious. the test is implemented * in ip6_input too, but we check here as well to * (1) reject bad packets earlier, and * (2) to be safe against future ip6_input change. */ if (IN6_IS_ADDR_V4COMPAT(in6)) { SDT_PROBE2(if_stf, , checkaddr6, out, -1, __LINE__); return (-1); } if (IN6_IS_ADDR_V4MAPPED(in6)) { SDT_PROBE2(if_stf, , checkaddr6, out, -1, __LINE__); return (-1); } SDT_PROBE2(if_stf, , checkaddr6, out, 0, __LINE__); return (0); } static int in_stf_input(struct mbuf *m, int off, int proto, void *arg) { struct stf_softc *sc = arg; struct ip ip; struct ip6_hdr *ip6; u_int8_t otos, itos; struct ifnet *ifp; struct nhop_object *nh; NET_EPOCH_ASSERT(); SDT_PROBE3(if_stf, , stf_input, in, m, off, proto); if (proto != IPPROTO_IPV6) { m_freem(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } m_copydata(m, 0, sizeof(struct ip), (caddr_t)&ip); if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { m_freem(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } ifp = STF2IFP(sc); #ifdef MAC mac_ifnet_create_mbuf(ifp, m); #endif /* * perform sanity check against outer src/dst. * for source, perform ingress filter as well. */ if (stf_checkaddr4(sc, &ip.ip_dst, NULL) < 0 || stf_checkaddr4(sc, &ip.ip_src, m->m_pkthdr.rcvif) < 0) { m_freem(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } otos = ip.ip_tos; m_adj(m, off); if (m->m_len < sizeof(*ip6)) { m = m_pullup(m, sizeof(*ip6)); if (!m) { SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } } ip6 = mtod(m, struct ip6_hdr *); /* * perform sanity check against inner src/dst. * for source, perform ingress filter as well. */ if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 || stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) { m_freem(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } /* * reject packets with private address range. * (requirement from RFC3056 section 2 1st paragraph) */ if ((IN6_IS_ADDR_6TO4(&ip6->ip6_src) && isrfc1918addr(&ip.ip_src)) || (IN6_IS_ADDR_6TO4(&ip6->ip6_dst) && isrfc1918addr(&ip.ip_dst))) { m_freem(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } /* * Ignore if the destination is the same stf interface because * all of valid IPv6 outgoing traffic should go interfaces * except for it. */ nh = fib6_lookup(sc->sc_fibnum, &ip6->ip6_dst, 0, 0, 0); if (nh == NULL) { m_free(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } if ((nh->nh_ifp == ifp) && (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &nh->gw6_sa.sin6_addr))) { m_free(m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } itos = IPV6_TRAFFIC_CLASS(ip6); if ((ifp->if_flags & IFF_LINK1) != 0) ip_ecn_egress(ECN_ALLOWED, &otos, &itos); else ip_ecn_egress(ECN_NOCARE, &otos, &itos); ip6->ip6_flow &= ~htonl(0xff << 20); ip6->ip6_flow |= htonl((u_int32_t)itos << 20); m->m_pkthdr.rcvif = ifp; if (bpf_peers_present(ifp->if_bpf)) { /* * We need to prepend the address family as * a four byte field. Cons up a dummy header * to pacify bpf. This is safe because bpf * will only read from the mbuf (i.e., it won't * try to free it or keep a pointer a to it). */ u_int32_t af = AF_INET6; bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); } /* * Put the packet to the network layer input queue according to the * specified address family. * See net/if_gif.c for possible issues with packet processing * reorder due to extra queueing. */ if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); M_SETFIB(m, ifp->if_fib); netisr_dispatch(NETISR_IPV6, m); SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__); return (IPPROTO_DONE); } static struct sockaddr_in * stf_getin4addr_in6(struct stf_softc *sc, struct sockaddr_in *sin, struct in6_addr addr6, struct in6_addr mask6, struct in6_addr in6) { int i; struct sockaddr_in *out; /* * When (src addr & src mask) != (in6 & src mask), * the dst is not in the 6rd domain. The IPv4 address must * not be used. */ for (i = 0; i < sizeof(addr6); i++) { if ((((u_char *)&addr6)[i] & ((u_char *)&mask6)[i]) != (((u_char *)&in6)[i] & ((u_char *)&mask6)[i])) { SDT_PROBE4(if_stf, , getin4addr_in6, out, &addr6, &mask6, &in6, NULL); return (NULL); } } /* After the mask check, use in6 instead of addr6. */ out = stf_getin4addr(sc, sin, in6, mask6); SDT_PROBE4(if_stf, , getin4addr_in6, out, &addr6, &mask6, &in6, out); return (out); } static struct sockaddr_in * stf_getin4addr(struct stf_softc *sc, struct sockaddr_in *sin, struct in6_addr addr6, struct in6_addr mask6) { struct in_addr *in; SDT_PROBE2(if_stf, , getin4addr, in, &addr6, &mask6); memset(sin, 0, sizeof(*sin)); in = &sin->sin_addr; if (IN6_IS_ADDR_6TO4(&addr6)) { /* 6to4 (RFC 3056) */ bcopy(GET_V4(&addr6), in, sizeof(*in)); if (isrfc1918addr(in)) return (NULL); } else { /* 6rd (RFC 5569) */ in_addr_t v4prefix; uint8_t *v6 = (uint8_t*)&addr6; uint64_t v6prefix; u_int plen; u_int v4suffixlen; v4prefix = 0; if (sc->v4prefixlen < 32) { v4suffixlen = 32 - sc->v4prefixlen; v4prefix = ntohl(sc->srcv4_addr) & (0xffffffffU << v4suffixlen); } else { MPASS(sc->v4prefixlen == 32); v4suffixlen = 32; } plen = in6_mask2len(&mask6, NULL); if (plen > 64) return (NULL); /* To make this simple we do not support prefixes longer than * 64 bits. RFC5969 says "a 6rd delegated prefix SHOULD be /64 * or shorter." so this is a moderately safe assumption. */ v6prefix = be64toh(*(uint64_t *)v6); /* Shift away the v6 prefix itself. */ v6prefix <<= plen; v6prefix >>= plen; /* Now shift away everything after the v4 address. */ v6prefix >>= 64 - plen - v4suffixlen; sin->sin_addr.s_addr = htonl(v4prefix | (uint32_t)v6prefix); } SDT_PROBE1(if_stf, , getin4addr, out, sin); return (sin); } static int stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct ifaddr *ifa; struct ifdrv *ifd; struct ifreq *ifr; struct sockaddr_in sin4; struct stf_softc *sc_cur; struct stfv4args args; int error, mtu; error = 0; sc_cur = ifp->if_softc; switch (cmd) { case SIOCSDRVSPEC: ifd = (struct ifdrv *)data; error = priv_check(curthread, PRIV_NET_ADDIFADDR); if (error) break; if (ifd->ifd_cmd == STF6RD_SV4NET) { if (ifd->ifd_len != sizeof(args)) { error = EINVAL; break; } bzero(&args, sizeof(args)); error = copyin(ifd->ifd_data, &args, ifd->ifd_len); if (error) break; if (args.v4_prefixlen < 1 || args.v4_prefixlen > 32) { error = EINVAL; break; } bcopy(&args.srcv4_addr, &sc_cur->srcv4_addr, sizeof(sc_cur->srcv4_addr)); sc_cur->v4prefixlen = args.v4_prefixlen; SDT_PROBE3(if_stf, , ioctl, sv4net, sc_cur->srcv4_addr, sc_cur->srcv4_addr, sc_cur->v4prefixlen); } else if (ifd->ifd_cmd == STF6RD_SBR) { if (ifd->ifd_len != sizeof(args)) { error = EINVAL; break; } bzero(&args, sizeof(args)); error = copyin(ifd->ifd_data, &args, ifd->ifd_len); if (error) break; sc_cur->braddr = args.braddr.s_addr; SDT_PROBE1(if_stf, , ioctl, sdstv4, sc_cur->braddr); } else error = EINVAL; break; case SIOCGDRVSPEC: ifd = (struct ifdrv *)data; if (ifd->ifd_cmd != STF6RD_GV4NET) { error = EINVAL; break; } if (ifd->ifd_len != sizeof(args)) { error = EINVAL; break; } bzero(&args, sizeof(args)); args.srcv4_addr.s_addr = sc_cur->srcv4_addr; args.braddr.s_addr = sc_cur->braddr; args.v4_prefixlen = sc_cur->v4prefixlen; error = copyout(&args, ifd->ifd_data, ifd->ifd_len); break; case SIOCSIFADDR: ifa = (struct ifaddr *)data; SDT_PROBE1(if_stf, , ioctl, ifaddr, ifa); if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { error = EAFNOSUPPORT; break; } if (stf_getin4addr(sc_cur, &sin4, satosin6(ifa->ifa_addr)->sin6_addr, satosin6(ifa->ifa_netmask)->sin6_addr) == NULL) { error = EINVAL; break; } ifp->if_flags |= IFF_UP; ifp->if_drv_flags |= IFF_DRV_RUNNING; break; case SIOCADDMULTI: case SIOCDELMULTI: ifr = (struct ifreq *)data; if (ifr && ifr->ifr_addr.sa_family == AF_INET6) ; else error = EAFNOSUPPORT; break; case SIOCGIFMTU: break; case SIOCSIFMTU: ifr = (struct ifreq *)data; mtu = ifr->ifr_mtu; /* RFC 4213 3.2 ideal world MTU */ if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20) return (EINVAL); ifp->if_mtu = mtu; break; default: error = EINVAL; break; } return (error); }