/* $FreeBSD$ */ /* $KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $ */ /*- * Copyright (C) 2000 WIDE Project. * Copyright (c) 2010 Hiroki Sato * Copyright (c) 2013 Ermal Luçi * 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 + 6rd (RFC5569) support. * * 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. * * 6rd (RFC5569 & RFC5969) extension is enabled when an IPv6 GUA other than * 2002::/16 is assigned. The stf(4) recognizes a 32-bit just after * prefixlen as the IPv4 address of the 6rd customer site. The * prefixlen must be shorter than 32. * */ #include "opt_inet.h" #include "opt_inet6.h" #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 #define STF_DEBUG 1 #if STF_DEBUG > 3 #define ip_sprintf(buf, a) \ sprintf(buf, "%u.%u.%u.%u", \ (ntohl((a)->s_addr)>>24)&0xFF, \ (ntohl((a)->s_addr)>>16)&0xFF, \ (ntohl((a)->s_addr)>>8)&0xFF, \ (ntohl((a)->s_addr))&0xFF); #endif #if STF_DEBUG #define DEBUG_PRINTF(a, ...) \ do { \ if (V_stf_debug >= a) \ printf(__VA_ARGS__); \ } while (0) #else #define DEBUG_PRINTF(a, ...) #endif SYSCTL_DECL(_net_link); static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW, 0, "6to4 Interface"); static VNET_DEFINE(int, stf_route_cache) = 0; #define V_stf_route_cache VNET(stf_route_cache) SYSCTL_VNET_INT(_net_link_stf, OID_AUTO, route_cache, CTLFLAG_RW, &VNET_NAME(stf_route_cache), 0, "Enable caching of IPv4 routes for 6to4 output."); #if STF_DEBUG static VNET_DEFINE(int, stf_debug) = 0; #define V_stf_debug VNET(stf_debug) SYSCTL_VNET_INT(_net_link_stf, OID_AUTO, stf_debug, CTLFLAG_RW, &VNET_NAME(stf_debug), 0, "Enable displaying verbose debug message of stf interfaces"); #endif static int stf_permit_rfc1918 = 1; TUNABLE_INT("net.link.stf.permit_rfc1918", &stf_permit_rfc1918); SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RW | CTLFLAG_TUN, &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses"); #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 dstv4_addr; in_addr_t srcv4_addr; in_addr_t inaddr; u_int v4prefixlen; union { struct route __sc_ro4; struct route_in6 __sc_ro6; /* just for safety */ } __sc_ro46; #define sc_ro __sc_ro46.__sc_ro4 struct mtx sc_mtx; u_int sc_fibnum; const struct encaptab *encap_cookie; u_int sc_flags; LIST_ENTRY(stf_softc) stf_list; }; #define STF2IFP(sc) ((sc)->sc_ifp) static const char stfname[] = "stf"; static struct mtx stf_mtx; static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface"); static VNET_DEFINE(LIST_HEAD(, stf_softc), stf_softc_list); #define V_stf_softc_list VNET(stf_softc_list) #define STF_LOCK_INIT(sc) mtx_init(&(sc)->sc_mtx, "stf softc", \ NULL, MTX_DEF); #define STF_LOCK_DESTROY(sc) mtx_destroy(&(sc)->sc_mtx) #define STF_LOCK(sc) mtx_lock(&(sc)->sc_mtx) #define STF_UNLOCK(sc) mtx_unlock(&(sc)->sc_mtx) #define STF_LOCK_ASSERT(sc) mtx_assert(&(sc)->sc_mtx, MA_OWNED) static const int ip_stf_ttl = 40; extern struct domain inetdomain; struct protosw in_stf_protosw = { .pr_type = SOCK_RAW, .pr_domain = &inetdomain, .pr_protocol = IPPROTO_IPV6, .pr_flags = PR_ATOMIC|PR_ADDR, .pr_input = in_stf_input, .pr_output = (pr_output_t *)rip_output, .pr_ctloutput = rip_ctloutput, .pr_usrreqs = &rip_usrreqs }; static int stfmodevent(module_t, int, void *); static int stf_encapcheck(const struct mbuf *, int, int, void *); static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *); 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 void stf_rtrequest(int, struct rtentry *, struct rt_addrinfo *); static int stf_ioctl(struct ifnet *, u_long, caddr_t); #define STF_GETIN4_USE_CACHE 1 static struct sockaddr_in *stf_getin4addr(struct stf_softc *, struct sockaddr_in *, struct ifaddr *, int); static struct sockaddr_in *stf_getin4addr_in6(struct stf_softc *, struct sockaddr_in *, struct ifaddr *, const struct in6_addr *); static struct sockaddr_in *stf_getin4addr_sin6(struct stf_softc *, struct sockaddr_in *, struct ifaddr *, struct sockaddr_in6 *); static int stf_clone_create(struct if_clone *, int, caddr_t); static void stf_clone_destroy(struct ifnet *); static struct if_clone *stf_cloner; static int stf_clone_create(struct if_clone *ifc, int unit, caddr_t params) { struct stf_softc *sc; struct ifnet *ifp; sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO); sc->sc_fibnum = curthread->td_proc->p_fibnum; ifp = STF2IFP(sc) = if_alloc(IFT_STF); if (sc->sc_ifp == NULL) { free(sc, M_STF); return (ENOMEM); } STF_LOCK_INIT(sc); ifp->if_softc = sc; if_initname(ifp, stfname, unit); sc->encap_cookie = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck, &in_stf_protosw, sc); if (sc->encap_cookie == NULL) { if_printf(ifp, "attach failed\n"); if_free(ifp); free(sc, M_STF); return (ENOMEM); } 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)); mtx_lock(&stf_mtx); LIST_INSERT_HEAD(&V_stf_softc_list, sc, stf_list); mtx_unlock(&stf_mtx); return (0); } static void stf_clone_destroy(struct ifnet *ifp) { struct stf_softc *sc = ifp->if_softc; int err; mtx_lock(&stf_mtx); LIST_REMOVE(sc, stf_list); mtx_unlock(&stf_mtx); err = encap_detach(sc->encap_cookie); KASSERT(err == 0, ("Unexpected error detaching encap_cookie")); bpfdetach(ifp); if_detach(ifp); if_free(ifp); STF_LOCK_DESTROY(sc); free(sc, M_STF); } static void vnet_stf_init(const void *unused __unused) { LIST_INIT(&V_stf_softc_list); } VNET_SYSINIT(vnet_stf_init, SI_SUB_PSEUDO, SI_ORDER_MIDDLE, vnet_stf_init, NULL); static int stfmodevent(module_t mod, int type, void *data) { switch (type) { case MOD_LOAD: mtx_init(&stf_mtx, "stf_mtx", NULL, MTX_DEF); stf_cloner = if_clone_simple(stfname, stf_clone_create, stf_clone_destroy, 0); break; case MOD_UNLOAD: if_clone_detach(stf_cloner); mtx_destroy(&stf_mtx); 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, 1); static int stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg) { struct ip ip; struct in6_ifaddr *ia6; struct sockaddr_in ia6_in4addr; struct sockaddr_in ia6_in4mask; struct sockaddr_in *sin; struct stf_softc *sc; struct ifnet *ifp; int ret = 0; DEBUG_PRINTF(1, "%s: enter\n", __func__); sc = (struct stf_softc *)arg; if (sc == NULL) return 0; ifp = STF2IFP(sc); if ((ifp->if_flags & IFF_UP) == 0) return 0; /* IFF_LINK0 means "no decapsulation" */ if ((ifp->if_flags & IFF_LINK0) != 0) return 0; if (proto != IPPROTO_IPV6) return 0; /* LINTED const cast */ m_copydata((struct mbuf *)(uintptr_t)m, 0, sizeof(ip), (caddr_t)&ip); if (ip.ip_v != 4) return 0; /* Lookup an ia6 whose IPv4 addr encoded in the IPv6 addr is valid. */ ia6 = stf_getsrcifa6(ifp); if (ia6 == NULL) return 0; if (sc->srcv4_addr != INADDR_ANY) { sin = &ia6_in4addr; sin->sin_addr.s_addr = sc->srcv4_addr; sin->sin_family = AF_INET; } else { sin = stf_getin4addr(sc, &ia6_in4addr, &ia6->ia_ifa, STF_GETIN4_USE_CACHE); if (sin == NULL) return (0); } #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip6_sprintf(buf, &satosin6(ia6->ia_ifa.ifa_addr)->sin6_addr); DEBUG_PRINTF(1, "%s: ia6->ia_ifa.ifa_addr = %s\n", __func__, buf); ip6_sprintf(buf, &ia6->ia_addr.sin6_addr); DEBUG_PRINTF(1, "%s: ia6->ia_addr = %s\n", __func__, buf); ip6_sprintf(buf, &satosin6(ia6->ia_ifa.ifa_netmask)->sin6_addr); DEBUG_PRINTF(1, "%s: ia6->ia_ifa.ifa_netmask = %s\n", __func__, buf); ip6_sprintf(buf, &ia6->ia_prefixmask.sin6_addr); DEBUG_PRINTF(1, "%s: ia6->ia_prefixmask = %s\n", __func__, buf); ip_sprintf(buf, &ia6_in4addr.sin_addr); DEBUG_PRINTF(1, "%s: ia6_in4addr.sin_addr = %s\n", __func__, buf); ip_sprintf(buf, &ip.ip_src); DEBUG_PRINTF(1, "%s: ip.ip_src = %s\n", __func__, buf); ip_sprintf(buf, &ip.ip_dst); DEBUG_PRINTF(1, "%s: ip.ip_dst = %s\n", __func__, buf); } #endif /* * check if IPv4 dst matches the IPv4 address derived from the * local 6to4 address. * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:... */ DEBUG_PRINTF(1, "%s: check1: ia6_in4addr.sin_addr == ip.ip_dst?\n", __func__); if (ia6_in4addr.sin_addr.s_addr != ip.ip_dst.s_addr) { DEBUG_PRINTF(1, "%s: check1: false. Ignore this packet.\n", __func__); goto freeit; } DEBUG_PRINTF(1, "%s: check2: ia6->ia_addr is 2002::/16?\n", __func__); if (IN6_IS_ADDR_6TO4(&ia6->ia_addr.sin6_addr)) { /* 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 */ DEBUG_PRINTF(1, "%s: check2: true.\n", __func__); memcpy(&ia6_in4mask.sin_addr, GET_V4(&ia6->ia_prefixmask.sin6_addr), sizeof(ia6_in4mask)); #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip_sprintf(buf, &ia6_in4addr.sin_addr); DEBUG_PRINTF(1, "%s: ia6->ia_addr = %s\n", __func__, buf); ip_sprintf(buf, &ip.ip_src); DEBUG_PRINTF(1, "%s: ip.ip_src = %s\n", __func__, buf); ip_sprintf(buf, &ia6_in4mask.sin_addr); DEBUG_PRINTF(1, "%s: ia6->ia_prefixmask = %s\n", __func__, buf); DEBUG_PRINTF(1, "%s: check3: ia6_in4addr.sin_addr & mask == ip.ip_src & mask\n", __func__); } #endif if ((ia6_in4addr.sin_addr.s_addr & ia6_in4mask.sin_addr.s_addr) != (ip.ip_src.s_addr & ia6_in4mask.sin_addr.s_addr)) { DEBUG_PRINTF(1, "%s: check3: false. Ignore this packet.\n", __func__); goto freeit; } } else { /* 6rd (RFC 5569) */ DEBUG_PRINTF(1, "%s: check2: false. 6rd.\n", __func__); /* * 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. */ } DEBUG_PRINTF(1, "%s: all clear!\n", __func__); /* stf interface makes single side match only */ ret = 32; freeit: ifa_free(&ia6->ia_ifa); return (ret); } static struct in6_ifaddr * stf_getsrcifa6(struct ifnet *ifp) { struct ifaddr *ifa; struct in_ifaddr *ia4; struct sockaddr_in *sin; struct sockaddr_in in4; struct stf_softc *sc; sc = ifp->if_softc; if_addr_rlock(ifp); TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; if (sc->srcv4_addr != INADDR_ANY) { in4.sin_addr.s_addr = sc->srcv4_addr; sin = &in4; } else if ((sin = stf_getin4addr(ifp->if_softc, &in4, ifa, STF_GETIN4_USE_CACHE)) == NULL) continue; LIST_FOREACH(ia4, INADDR_HASH(sin->sin_addr.s_addr), ia_hash) if (ia4->ia_addr.sin_addr.s_addr == sin->sin_addr.s_addr) break; if (ia4 == NULL) continue; #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip6_sprintf(buf, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr); DEBUG_PRINTF(1, "%s: ifa->ifa_addr->sin6_addr = %s\n", __func__, buf); ip_sprintf(buf, &ia4->ia_addr.sin_addr); DEBUG_PRINTF(1, "%s: ia4->ia_addr.sin_addr = %s\n", __func__, buf); } #endif ifa_ref(ifa); if_addr_runlock(ifp); return (ifatoia6(ifa)); } if_addr_runlock(ifp); return (NULL); } 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 route *cached_route; struct sockaddr_in *sin; struct sockaddr_in in4; struct sockaddr_in *dst4; u_int8_t tos; struct ip *ip; struct ip6_hdr *ip6; struct in6_ifaddr *ia6; int error; #ifdef MAC error = mac_ifnet_check_transmit(ifp, m); if (error) { m_freem(m); 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); ifp->if_oerrors++; 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. */ ia6 = stf_getsrcifa6(ifp); if (ia6 == NULL) { m_freem(m); ifp->if_oerrors++; return ENETDOWN; } if (m->m_len < sizeof(*ip6)) { m = m_pullup(m, sizeof(*ip6)); if (!m) { ifa_free(&ia6->ia_ifa); ifp->if_oerrors++; return ENOBUFS; } } ip6 = mtod(m, struct ip6_hdr *); tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; /* * 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. * ip6_dst: destination addr in the packet header. * dst6: destination addr specified in function argument. */ DEBUG_PRINTF(1, "%s: dst addr selection\n", __func__); sin = stf_getin4addr_in6(sc, &in4, &ia6->ia_ifa, &ip6->ip6_dst); if (sin == NULL) { if (sc->dstv4_addr != INADDR_ANY) in4.sin_addr.s_addr = sc->dstv4_addr; else { sin = stf_getin4addr_in6(sc, &in4, &ia6->ia_ifa, &dst6->sin6_addr); if (sin == NULL) { ifa_free(&ia6->ia_ifa); m_freem(m); ifp->if_oerrors++; return ENETUNREACH; } } } #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip_sprintf(buf, &in4.sin_addr); DEBUG_PRINTF(1, "%s: ip_dst = %s\n", __func__, buf); } #endif 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) { ifa_free(&ia6->ia_ifa); ifp->if_oerrors++; return ENOBUFS; } ip = mtod(m, struct ip *); bzero(ip, sizeof(*ip)); bcopy(&in4.sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)); if (sc->srcv4_addr != INADDR_ANY) in4.sin_addr.s_addr = sc->srcv4_addr; else { sin = stf_getin4addr_sin6(sc, &in4, &ia6->ia_ifa, &ia6->ia_addr); if (sin == NULL) { ifa_free(&ia6->ia_ifa); m_freem(m); ifp->if_oerrors++; return ENETUNREACH; } } bcopy(&in4.sin_addr, &ip->ip_src, sizeof(ip->ip_src)); #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip_sprintf(buf, &ip->ip_src); DEBUG_PRINTF(1, "%s: ip_src = %s\n", __func__, buf); } #endif ifa_free(&ia6->ia_ifa); 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); if (!V_stf_route_cache) { cached_route = NULL; goto sendit; } /* * Do we have a cached route? */ STF_LOCK(sc); dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst; if (dst4->sin_family != AF_INET || bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) { /* cache route doesn't match */ dst4->sin_family = AF_INET; dst4->sin_len = sizeof(struct sockaddr_in); bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr)); if (sc->sc_ro.ro_rt) { RTFREE(sc->sc_ro.ro_rt); sc->sc_ro.ro_rt = NULL; } } if (sc->sc_ro.ro_rt == NULL) { rtalloc_fib(&sc->sc_ro, sc->sc_fibnum); if (sc->sc_ro.ro_rt == NULL) { m_freem(m); ifp->if_oerrors++; STF_UNLOCK(sc); return ENETUNREACH; } if (sc->sc_ro.ro_rt->rt_ifp == ifp) { /* infinite loop detection */ m_free(m); ifp->if_oerrors++; STF_UNLOCK(sc); return ENETUNREACH; } } cached_route = &sc->sc_ro; sendit: M_SETFIB(m, sc->sc_fibnum); ifp->if_opackets++; DEBUG_PRINTF(1, "%s: ip_output dispatch.\n", __func__); error = ip_output(m, NULL, cached_route, 0, NULL, NULL); if (cached_route != NULL) STF_UNLOCK(sc); 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) == 10 << 24 || (ntohl(in->s_addr) & 0xfff00000) == (172 * 256 + 16) << 16 || (ntohl(in->s_addr) & 0xffff0000) == (192 * 256 + 168) << 16 )) 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 */ IN_IFADDR_RLOCK(); TAILQ_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) { IN_IFADDR_RUNLOCK(); return -1; } } IN_IFADDR_RUNLOCK(); /* * perform ingress filter */ if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) { struct sockaddr_in sin; struct rtentry *rt; bzero(&sin, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_len = sizeof(sin); sin.sin_addr = *in; rt = rtalloc1_fib((struct sockaddr *)&sin, 0, 0UL, sc->sc_fibnum); if (!rt || rt->rt_ifp != inifp) { #if 0 log(LOG_WARNING, "%s: packet from 0x%x dropped " "due to ingress filter\n", if_name(STF2IFP(sc)), (u_int32_t)ntohl(sin.sin_addr.s_addr)); #endif if (rt) RTFREE_LOCKED(rt); return -1; } RTFREE_LOCKED(rt); } return 0; } static int stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp) { /* * check 6to4 addresses */ if (IN6_IS_ADDR_6TO4(in6)) { struct in_addr in4; bcopy(GET_V4(in6), &in4, sizeof(in4)); return stf_checkaddr4(sc, &in4, inifp); } /* * 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) || IN6_IS_ADDR_V4MAPPED(in6)) return -1; return 0; } void in_stf_input(struct mbuf *m, int off) { int proto; struct stf_softc *sc; struct ip *ip; struct ip6_hdr *ip6; u_int8_t otos, itos; struct ifnet *ifp; struct route_in6 rin6; proto = mtod(m, struct ip *)->ip_p; if (proto != IPPROTO_IPV6) { m_freem(m); return; } ip = mtod(m, struct ip *); sc = (struct stf_softc *)encap_getarg(m); if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) { m_freem(m); return; } ifp = STF2IFP(sc); #ifdef MAC mac_ifnet_create_mbuf(ifp, m); #endif #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip_sprintf(buf, &ip->ip_dst); DEBUG_PRINTF(1, "%s: ip->ip_dst = %s\n", __func__, buf); ip_sprintf(buf, &ip->ip_src); DEBUG_PRINTF(1, "%s: ip->ip_src = %s\n", __func__, buf); } #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); return; } otos = ip->ip_tos; m_adj(m, off); if (m->m_len < sizeof(*ip6)) { m = m_pullup(m, sizeof(*ip6)); if (!m) return; } ip6 = mtod(m, struct ip6_hdr *); #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip6_sprintf(buf, &ip6->ip6_dst); DEBUG_PRINTF(1, "%s: ip6->ip6_dst = %s\n", __func__, buf); ip6_sprintf(buf, &ip6->ip6_src); DEBUG_PRINTF(1, "%s: ip6->ip6_src = %s\n", __func__, buf); } #endif /* * 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); return; } /* * 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); return; } /* * Ignore if the destination is the same stf interface because * all of valid IPv6 outgoing traffic should go interfaces * except for it. */ memset(&rin6, 0, sizeof(rin6)); rin6.ro_dst.sin6_len = sizeof(rin6.ro_dst); rin6.ro_dst.sin6_family = AF_INET6; memcpy(&rin6.ro_dst.sin6_addr, &ip6->ip6_dst, sizeof(rin6.ro_dst.sin6_addr)); rtalloc((struct route *)&rin6); if (rin6.ro_rt == NULL) { DEBUG_PRINTF(1, "%s: no IPv6 dst. Ignored.\n", __func__); m_free(m); return; } if ((rin6.ro_rt->rt_ifp == ifp) && (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &rin6.ro_dst.sin6_addr))) { DEBUG_PRINTF(1, "%s: IPv6 dst is the same stf. Ignored.\n", __func__); RTFREE(rin6.ro_rt); m_free(m); return; } RTFREE(rin6.ro_rt); itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff; 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); } DEBUG_PRINTF(1, "%s: netisr_dispatch(NETISR_IPV6)\n", __func__); /* * 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. */ ifp->if_ipackets++; ifp->if_ibytes += m->m_pkthdr.len; M_SETFIB(m, ifp->if_fib); netisr_dispatch(NETISR_IPV6, m); } /* ARGSUSED */ static void stf_rtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) { RT_LOCK_ASSERT(rt); rt->rt_mtu = rt->rt_ifp->if_mtu; } static struct sockaddr_in * stf_getin4addr_in6(struct stf_softc *sc, struct sockaddr_in *sin, struct ifaddr *ifa, const struct in6_addr *in6) { struct sockaddr_in6 sin6; DEBUG_PRINTF(1, "%s: enter.\n", __func__); if (ifa == NULL || in6 == NULL) return NULL; memset(&sin6, 0, sizeof(sin6)); memcpy(&sin6.sin6_addr, in6, sizeof(sin6.sin6_addr)); sin6.sin6_len = sizeof(sin6); sin6.sin6_family = AF_INET6; return(stf_getin4addr_sin6(sc, sin, ifa, &sin6)); } static struct sockaddr_in * stf_getin4addr_sin6(struct stf_softc *sc, struct sockaddr_in *sin, struct ifaddr *ifa, struct sockaddr_in6 *sin6) { struct in6_ifaddr ia6; int i; DEBUG_PRINTF(1, "%s: enter.\n", __func__); if (ifa == NULL || sin6 == NULL) return NULL; memset(&ia6, 0, sizeof(ia6)); memcpy(&ia6, ifatoia6(ifa), sizeof(ia6)); /* * Use prefixmask information from ifa, and * address information from sin6. */ ia6.ia_addr.sin6_family = AF_INET6; ia6.ia_ifa.ifa_addr = (struct sockaddr *)&ia6.ia_addr; ia6.ia_ifa.ifa_dstaddr = NULL; ia6.ia_ifa.ifa_netmask = (struct sockaddr *)&ia6.ia_prefixmask; #if STF_DEBUG > 3 { char buf[INET6_ADDRSTRLEN + 1]; memset(&buf, 0, sizeof(buf)); ip6_sprintf(buf, &sin6->sin6_addr); DEBUG_PRINTF(1, "%s: sin6->sin6_addr = %s\n", __func__, buf); ip6_sprintf(buf, &ia6.ia_addr.sin6_addr); DEBUG_PRINTF(1, "%s: ia6.ia_addr.sin6_addr = %s\n", __func__, buf); ip6_sprintf(buf, &ia6.ia_prefixmask.sin6_addr); DEBUG_PRINTF(1, "%s: ia6.ia_prefixmask.sin6_addr = %s\n", __func__, buf); } #endif /* * When (src addr & src mask) != (dst (sin6) addr & src mask), * the dst is not in the 6rd domain. The IPv4 address must * not be used. */ for (i = 0; i < sizeof(ia6.ia_addr.sin6_addr); i++) { if ((((u_char *)&ia6.ia_addr.sin6_addr)[i] & ((u_char *)&ia6.ia_prefixmask.sin6_addr)[i]) != (((u_char *)&sin6->sin6_addr)[i] & ((u_char *)&ia6.ia_prefixmask.sin6_addr)[i])) return NULL; } /* After the mask check, overwrite ia6.ia_addr with sin6. */ memcpy(&ia6.ia_addr, sin6, sizeof(ia6.ia_addr)); return(stf_getin4addr(sc, sin, (struct ifaddr *)&ia6, 0)); } static struct sockaddr_in * stf_getin4addr(struct stf_softc *sc, struct sockaddr_in *sin, struct ifaddr *ifa, int flags) { struct in_addr *in; struct sockaddr_in6 *sin6; struct in6_ifaddr *ia6; DEBUG_PRINTF(1, "%s: enter.\n", __func__); if (ifa == NULL || ifa->ifa_addr == NULL || ifa->ifa_addr->sa_family != AF_INET6) return NULL; sin6 = satosin6(ifa->ifa_addr); ia6 = ifatoia6(ifa); if ((flags & STF_GETIN4_USE_CACHE) && (ifa->ifa_dstaddr != NULL) && (ifa->ifa_dstaddr->sa_family == AF_INET)) { /* * XXX: ifa_dstaddr is used as a cache of the * extracted IPv4 address. */ memcpy(sin, satosin(ifa->ifa_dstaddr), sizeof(*sin)); #if STF_DEBUG > 3 { char tmpbuf[INET6_ADDRSTRLEN + 1]; memset(&tmpbuf, 0, INET6_ADDRSTRLEN); ip_sprintf(tmpbuf, &sin->sin_addr); DEBUG_PRINTF(1, "%s: cached address was used = %s\n", __func__, tmpbuf); } #endif return (sin); } memset(sin, 0, sizeof(*sin)); in = &sin->sin_addr; #if STF_DEBUG > 3 { char tmpbuf[INET6_ADDRSTRLEN + 1]; memset(&tmpbuf, 0, INET6_ADDRSTRLEN); ip6_sprintf(tmpbuf, &sin6->sin6_addr); DEBUG_PRINTF(1, "%s: sin6->sin6_addr = %s\n", __func__, tmpbuf); } #endif if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) { /* 6to4 (RFC 3056) */ bcopy(GET_V4(&sin6->sin6_addr), in, sizeof(*in)); if (isrfc1918addr(in)) return NULL; } else { /* 6rd (RFC 5569) */ struct in6_addr buf; u_char *p = (u_char *)&buf; u_char *q = (u_char *)&in->s_addr; u_int residue = 0, v4residue = 0; u_char mask, v4mask = 0; int i, j; u_int plen, loop; /* * 6rd-relays IPv6 prefix is located at a 32-bit just * after the prefix edge. */ plen = in6_mask2len(&satosin6(ifa->ifa_netmask)->sin6_addr, NULL); if (64 < plen) { DEBUG_PRINTF(1, "prefixlen is %d\n", plen); return NULL; } loop = 4; /* Normal 6rd operation */ memcpy(&buf, &sin6->sin6_addr, sizeof(buf)); if (sc->v4prefixlen != 0 && sc->v4prefixlen != 32) { v4residue = sc->v4prefixlen % 8; } p += plen / 8; //plen -= 32; residue = plen % 8; mask = ((u_char)(-1) >> (8 - residue)); if (v4residue) { loop++; v4mask = ((u_char)(-1) << v4residue); } /* * The p points head of the IPv4 address part in * bytes. The residue is a bit-shift factor when * prefixlen is not a multiple of 8. */ DEBUG_PRINTF(2, "residue = %d 0x%x\n", residue, mask); for (j = 0, i = (loop - (sc->v4prefixlen / 8)); i < loop; j++, i++) { if (residue) { q[i] = ((p[j] & mask) << (8 - residue)); q[i] |= ((p[j + 1] >> residue) & mask); DEBUG_PRINTF(2, "FINAL i = %d q[%d] - p[%d/%d] %x\n", i, q[i], p[j], p[j + 1] >> residue, q[i]); } else { q[i] = p[j]; DEBUG_PRINTF(2, "FINAL q[%d] - p[%d] %x\n", q[i], p[j], q[i]); } } if (v4residue) { q[loop - (sc->v4prefixlen / 8)] &= v4mask; if (sc->v4prefixlen > 0 && sc->v4prefixlen < 32) in->s_addr |= sc->inaddr; } //if (in->s_addr != sc->srcv4_addr) // printf("Wrong decoded address %x/%x!!!!\n", in->s_addr, sc->srcv4_addr); } #if STF_DEBUG > 3 { char tmpbuf[INET6_ADDRSTRLEN + 1]; memset(&tmpbuf, 0, INET_ADDRSTRLEN); ip_sprintf(tmpbuf, in); DEBUG_PRINTF(1, "%s: in->in_addr = %s\n", __func__, tmpbuf); DEBUG_PRINTF(1, "%s: leave\n", __func__); } #endif if (flags & STF_GETIN4_USE_CACHE) { DEBUG_PRINTF(1, "%s: try to access ifa->ifa_dstaddr.\n", __func__); ifa->ifa_dstaddr = (struct sockaddr *)&ia6->ia_dstaddr; DEBUG_PRINTF(1, "%s: try to memset 0 to ia_dstaddr.\n", __func__); memset(&ia6->ia_dstaddr, 0, sizeof(ia6->ia_dstaddr)); DEBUG_PRINTF(1, "%s: try to memcpy ifa->ifa_dstaddr.\n", __func__); memcpy((struct sockaddr_in *)ifa->ifa_dstaddr, sin, sizeof(struct sockaddr_in)); DEBUG_PRINTF(1, "%s: try to set sa_family.\n", __func__); ifa->ifa_dstaddr->sa_family = AF_INET; DEBUG_PRINTF(1, "%s: in->in_addr is stored in ifa_dstaddr.\n", __func__); } return (sin); } static int stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct stf_softc *sc, *sc_cur; struct ifaddr *ifa; struct ifreq *ifr; struct sockaddr_in in4; struct stfv4args args; struct in6_ifaddr *ia6; struct ifdrv *ifd; 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 == STF_SV4NET) { if (ifd->ifd_len != sizeof(args)) { error = EINVAL; break; } mtx_lock(&stf_mtx); LIST_FOREACH(sc, &V_stf_softc_list, stf_list) { if (sc == sc_cur) continue; if (sc->inaddr == 0 || sc->v4prefixlen == 0) continue; if ((ntohl(sc->inaddr) & ((uint32_t)(-1) << sc_cur->v4prefixlen)) == ntohl(sc_cur->inaddr)) { error = EEXIST; mtx_unlock(&stf_mtx); return (error); } if ((ntohl(sc_cur->inaddr) & ((uint32_t)(-1) << sc->v4prefixlen)) == ntohl(sc->inaddr)) { error = EEXIST; mtx_unlock(&stf_mtx); return (error); } } mtx_unlock(&stf_mtx); bzero(&args, sizeof args); error = copyin(ifd->ifd_data, &args, ifd->ifd_len); if (error) break; sc_cur->srcv4_addr = args.inaddr.s_addr; sc_cur->inaddr = ntohl(args.inaddr.s_addr); sc_cur->inaddr &= ((uint32_t)(-1) << args.prefix); sc_cur->inaddr = htonl(sc_cur->inaddr); sc_cur->v4prefixlen = args.prefix; if (sc_cur->v4prefixlen == 0) sc_cur->v4prefixlen = 32; } else if (ifd->ifd_cmd == STF_SDSTV4) { 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->dstv4_addr = args.dstv4_addr.s_addr; } else error = EINVAL; break; case SIOCGDRVSPEC: ifd = (struct ifdrv *) data; if (ifd->ifd_len != sizeof(args)) { error = EINVAL; break; } if (ifd->ifd_cmd != STF_GV4NET) { error = EINVAL; break; } bzero(&args, sizeof args); args.inaddr.s_addr = sc_cur->srcv4_addr; args.dstv4_addr.s_addr = sc_cur->dstv4_addr; args.prefix = sc_cur->v4prefixlen; error = copyout(&args, ifd->ifd_data, ifd->ifd_len); break; case SIOCSIFADDR: ifa = (struct ifaddr *)data; if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) { error = EAFNOSUPPORT; break; } if (stf_getin4addr(sc_cur, &in4, ifa, 0) == NULL) { error = EINVAL; break; } /* * Sanity check: if more than two interfaces have IFF_UP, do * if_down() for all of them except for the specified one. */ mtx_lock(&stf_mtx); LIST_FOREACH(sc, &V_stf_softc_list, stf_list) { if (sc == sc_cur) continue; if ((ia6 = stf_getsrcifa6(sc->sc_ifp)) == NULL) continue; if (IN6_ARE_ADDR_EQUAL(&ia6->ia_addr.sin6_addr, &ifatoia6(ifa)->ia_addr.sin6_addr)) { error = EEXIST; ifa_free(&ia6->ia_ifa); break; } ifa_free(&ia6->ia_ifa); } mtx_unlock(&stf_mtx); /* * XXX: ifa_dstaddr is used as a cache of the * extracted IPv4 address. */ if (ifa->ifa_dstaddr != NULL) ifa->ifa_dstaddr->sa_family = AF_UNSPEC; ifa->ifa_rtrequest = stf_rtrequest; 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; }